1. Technical Field
The present invention relates to a physical quantity detection circuit, a physical quantity detection device, an electronic apparatus, and a vehicle.
2. Related Art
At present, there are used physical quantity detection devices capable of detecting a variety of physical quantities, such as an acceleration sensor for detecting acceleration and a gyro sensor for detecting angular velocity, are widely used in a variety of systems and electronic apparatuses. For example, in JP-A-2015-135245, there is disclosed a physical quantity detection device configured by connecting a physical quantity detection circuit to a differential capacitive sensor, wherein the physical quantity detection circuit is provided with a QV amplifier, a programmable-gain amplifier (PGA), and an analog-digital converter (ADC).
In the physical quantity detection device, which performs analog processing on an analog signal output by the physical quantity detection element, and then converts the result into a digital signal using the ADC as in the case of the physical quantity detection device described in JP-A-2015-135245, it is necessary to make the drive frequency of the physical quantity detection element and the sampling frequency of the ADC coincide with each other, or to perform the conversion into a DC signal with a sample-and-hold circuit using the drive frequency. In the case of making the drive frequency and the sampling frequency of the ADC coincide with each other, an anti-aliasing filter cannot be provided, and therefore, reduction of noise is difficult due to the aliasing noise caused by the sampling in the ADC. Further, in the case of disposing the sample-and-hold circuit and the anti-aliasing filter in the anterior stage of the ADC, there occurs the aliasing noise due to the sample-and-hold circuit. Further, the anti-aliasing filter cannot be made larger in view of the circuit speed and the circuit area, and therefore, the reduction of noise is difficult.